Generally, an electrical connector includes a dielectric housing mounting at least one electrically conductive terminal therein. The terminal is electrically connected to another circuit component, such as a discrete electrical wire. Connectors often are employed in mateable pairs such that each terminal and the housing of one connector are mateable with a corresponding terminal and the housing of another connector.
The terminals of electrical connectors frequently are very small components, such as components that are stamped and/or formed from thin sheet metal material. A poor quality electrical connection may occur if one or more terminals are not properly seated in its respective housing. The improper seating of a terminal in a housing may occur if the terminal is not fully inserted into the housing during the initial assembly of the connector or if the terminal is vibrated or pulled out of its fully seated condition during use of the connector. Failures of this type are a particular concern in the automotive industry where electrical components are subjected to vibration almost continuously during normal usage and are subjected to direct force during some maintenance. To avoid these problems, the automotive industry often requires connectors to be provided with some form of a terminal position assurance (TPA) system to detect incomplete insertion of the terminals and or to move inserted terminals to their fully inserted positions. The automotive industry also requires locking means for locking the terminals in the housing, and a TPA system or device may also perform this function.
Heretofore, terminals typically have been locked in a connector housing using either a locking tang on the terminal that engages a locking surface on the connector housing or a resilient locking lance on the housing that engages a locking surface on a body of the terminal. In automotive applications, tanged terminals are not as desirable as “smooth body” terminals which engage locking lances on the housing, because the tanged terminals are prone to snagging and breakage during assembly operations.
Locking lances on a connector housing for engaging locking surfaces on smooth body terminals typically comprise resilient or flexible fingers having locking hooks at the distal ends of the fingers for engaging the locking surfaces on the terminal body. The connector housing typically is molded of plastic material, and the flexible fingers are molded in the terminal cavities of the housing and require space directly behind the flexible fingers to allow the fingers to deflect when the terminals are inserted into the cavities. This additional space results in the overall size of the connector being enlarged in applications where, to the contrary, miniaturization is highly desirable. The present invention solves these various problems in an improved terminal position assurance system in an electrical connector of the character described.